L’image des Samnites depuis Tite-Live. Une analyse historiographique

Une image domine la perception du peuple samnite, celle d’une arriération montagnarde qui confine à la barbarie. Le propos de cet article historiographique est d’étudier comment cette image s’est construite et a perduré. On examine le portrait de ce peuple par les Anciens, puis la perpétuation, dans un choix d’ouvrages modernes, d’un discours récurrent sur les Samnites et sur leurs rapports avec Rome. La dichotomie du montagnard tribal et de l’homme des plaines, citadin et civilisé, n’a pas été véritablement dépassée, même si l’approche des Samnites par les auteurs choisis a été diverse, liée aux questionnements politiques, culturels et scientifiques de leurs époques respectives. Des contradictions, lisibles chez tous les auteurs, et quelques rares remises en question de l’image dominante, incitent pourtant à avoir une vision plus complexe de la localisation des Samnites, de l’opposition culturelle romano-samnite, enfin de la construction et de l’évolution dans le temps de ces deux aspectsOne image prevails in the perception of the Samnite people: the backwardness ­verging on barbarity of a hillside people. The purpose of this historiographic article is to examine how that image came to be constructed and how it left a lasting impression. We examine the portrait of that people by the Ancients, then the permanence, through a selection of modern works, of a recurring discourse on the Samnites and their relations to Rome. The dichotomy between the tribal mountain dweller and the man of the plains, inhabiting cities and civilized, has not really been overcome even if the approach of the Samnites by the selected authors has been varied, bound up as it has been with the political, cultural and scientific questionings of their respective times. Contradictions perceptible in all the authors and the scant questioning of the dominant image, incite one, however, to have a more complex view of the localization of the Samnites, of the Romano-Samnite cultural opposition, lastly of the building up and evolution in time of those two aspect

Changes in Parasitoid Communities Over Time and Space: A Historical Case Study of the Maize Pest Ostrinia nubilalis

Understanding the ways in which human environmental modifications affect biodiversity is a key challenge in conservation planning, pest control and evolutionary ecology. Parasitoid communities, particularly those associated with agricultural pests, may be susceptible to such modifications. We document here changes in the larval parasitoid communities of Ostrinia nubilalis — the main pest of maize — and its sibling species O. scapulalis, based on two historical datasets, one collected from 1921–1928 and the other from 2001–2005. Each of these datasets encompasses several years and large geographical areas and was based on several thousands/millions of host larvae. The 80-year interval between the two datasets was marked by a decrease in O. nubilalis parasitism to about two thirds its initial level, mostly due to a decrease in the rate of parasitism by hymenopterans. However, a well balanced loss and gain of species ensured that species richness remained stable. Conversely, O. scapulalis displayed stable rates of parasitism over this period, with a decline in the species richness of its parasitoid community. Rates of parasitism and species richness in regions colonized by O. nubilalis during the 1950s were one half to one third those in regions displaying long-term colonisation by this pest. During the recent human activity-driven expansion of its range, O. nubilalis has neither captured native parasitoids nor triggered parasite spill back or spill over

Sustainability of bio-jetfuel in Malaysia

Aviation represents a small but growing share of global CO2 emissions (2-3%), and Southeast Asia is where this industry grows the fastest. The industry targets 50% reduction in net CO2 emission by 2050, and will need at least 2 million tonnes of biofuel by 2020. In Southeast Asia, competition between natural spaces (such as tropical forests) and biofuel development should be avoided. A complex interaction of political, sociological and natural factors influence the logistics, the infrastructures and the potential sustainability of biofuel. The contrasted growing conditions, and the geographically scattered nature of the potential resources for aviation industry, add to the complexity. Building visions and actions necessitates a range of assessments and researches, to insure sustainability of appropriate scenarios and pathways. In Malaysia, a consortium established a Center of Excellence on Biomass Valorisation for aviation, in order to study the biomass feedstocks and pathways which are necessary to meet the industry target, and to ensure sustainability

Considérations numismatiques sur la guerre sociale

Numismatic considerations on the civil war. Essential source though it is, the series of coins minted by the Italian insurgents in the Civil War has not been given the study it deserved. A new approach rules out in the first place the strict partition between Marses and the Samnites and the existence of two mints, then suggests the theme of a conspiracy held together by a religious bond, with notably the presence of Bacchus and the Italian bull but also of Hercules who reminds one of the hillside character of the insurgents' living conditions. Chronologically and granted an evolution in the style and language of the coins, it looks as if they were testifying to a return of the Italians to their cultural roots during the war. This should entail the conclusion that a constant dialogue between literary and numismatic sources may still prove extremely fruitful.Source essentielle, la série monétaire frappée par les Italiens insurgés de la guerre sociale n'a pourtant pas connu l'étude qu'elle aurait méritée. Après avoir remis en cause la séparation stricte entre Marses et Samnites et l'existence de deux ateliers de frappe, une nouvelle approche, à partir du style des monnaies, suggère le thème de la conjuration appuyée sur un lien religieux, avec notamment la présence de Bacchus, du taureau italien, mais aussi d'Hercule qui rappelle le cadre d'existence montagnard des insurgés. Sur le plan chronologique, si l'on admet une évolution progressive du style et de la langue des monnaies, il semble que l'on assiste à un ré-enracinement culturel des Italiens pendant la guerre. On concevra donc que le dialogue constant entre les sources littéraire et numismatique peut encore se révéler extrêmement fécond.Eychenne Jean-Marc. Considérations numismatiques sur la guerre sociale. In: Pallas, 36/1990. Littérature Histoire Archéologie Cosmologie. pp. 71-87

Withdrawal of maize protection by herbicides and insecticides increases mycotoxins contamination near maximum thresholds

Environmental and economic issues affect decision-making for whether or not to control small infestations of pests and pathogens in crops. Even where no crop yield loss is expected, other risks may be evident, such as the slow accumulation of pathogen inocula. The prevalence of toxins, arising from biotic interactions with fungal diseases, can alter crop quality rather than quantity. Thus, farmer decisions for whether to tolerate pest infestation must take into account several direct and immediate and/or delayed potential risks. Published scientific evidence on the co-occurrence of risk factors resulting from the presence of different pests and pathogens are largely absent, and this has stifled the adoption of integrated pest management. Here, we tested how the withdrawal of herbicide and insecticide protection in maize, alone and in combination, might induce higher prevalence of up to 23 mycotoxins in the crop at harvest. The experiment was conducted over 4 years in 29 fields in the south west of France. The test involved a comparison of paired samples collected from treated and untreated plots. All nine major mycotoxins that were observed in more than 4 % of the samples showed highly variable concentrations both between fields and years. The overall trend following the cessation of pesticide protection, however, is for higher levels of mycotoxins and up to a six-fold increased in nivalenol mean concentration (to 202.3 mu g kg(-1) of maize seeds) compared to its treated control. Overall mycotoxin concentrations approached 55-67 % of their maximum acceptable rate, a situation of reduced security margin that could lead to economic penalties and market restrictions. We found that the removal of herbicides had a greater impact than that of insecticides on the prevalence of mycotoxins, which differs from the expectation stated in the literature. This finding is further reinforced by the observation that certain species of weeds harbor several species of Fusarium. This means that weeds not only play a role as crop competitors but also as reservoirs of inoculum in the field. Our findings illustrate the importance of sanitary evaluation when the implementation of new cropping systems will alter the distribution and occurrence of pests and pathogens

Biocontrol of Ostrinia nubilalis and Sesamia nonagrioides by Bt maize in South Western France : search of biological indicators by a model-based approach for managing mycotoxin risks

International audienc

Ostrinia nubilalis parasitism and the field abundance of non-target insects in transgenic Bacillus thuringiensis corn ( Zea mays )

International audienceIn this study, we evaluated in field trials the effects on non-target species, of transgenic corn producing the Cry1Ab toxin of Bacillus thuringiensis (Bt). In 1998, we collected Ostrinia nubilalis (Hübner) larvae from transgenic Bt corn (Novartis Hybrid 176) and non-Bt corn at four geographical sites. We found a significant variation in parasitism by the tachinids Lydella thompsoni (Herting) and Pseudoperichaeta nigrolineata (Walker) among sites, and more parasitism in non-Bt than in Bt fields. The Bt effect did not vary significantly among fields. In 1999, we performed a field experiment at two sites, comparing the temporal abundance of non-target arthropods in Bt corn (Monsanto Hybrid MON810) and non-Bt corn. The non-target insects studied included the aphids Metopolophium dirhodum (Walker), Rhopalosiphum padi (L.) and Sitobion avenae (F.), the bug Orius insidiosus (Say), the syrphid Syrphus corollae (Meigen), the ladybird Coccinella septempunctata (L.), the lacewing Chrysoperla carnea (Stephens), thrips and hymenopteran parasitoids. For all species but one, the number of individuals varied greatly over the season but did not differ between the types of corn. The only exception was thrips which, at one site, was significantly more abundant in Bt corn than in non-Bt corn. However this difference did not remain significant when we took the multiple tests into account. Implications for pest resistance management, population dynamics and risk assessment are discussed

RNA interference identifies domesticated viral genes involved in assembly and trafficking of virus-derived particles in ichneumonid wasps

International audienceThere are many documented examples of viral genes retained in the genomes of multicellular organisms that may in some cases bring new beneficial functions to the receivers. The ability of certain ichneumonid parasitic wasps to produce virus-derived particles, the so-called ichnoviruses (IVs), not only results from the capture and domestication of single viral genes but of almost entire ancestral virus genome(s). Indeed, following integration into wasp chromosomal DNA, the putative and still undetermined IV ancestor(s) evolved into encoding a 'virulence gene delivery vehicle' that is now required for successful infestation of wasp hosts. Several putative viral genes, which are clustered in distinct regions of wasp genomes referred to as IVSPERs (Ichnovirus Structural Protein Encoding Regions), have been assumed to be involved in virus-derived particles morphogenesis, but this question has not been previously functionally addressed. In the present study, we have successfully combined RNA interference and transmission electron microscopy to specifically identify IVSPER genes that are responsible for the morphogenesis and trafficking of the virus-derived particles in ovarian cells of the ichneumonid wasp Hyposoter didymator. We suggest that ancestral viral genes retained within the genomes of certain ichneumonid parasitoids possess conserved functions which were domesticated for the purpose of assembling viral vectors for the delivery of virulence genes to parasitized host animals. Author summary Thousands of parasitic wasp from the ichneumonid family rely on virus-derived particles, named Ichnoviruses (Polydnavirus family), to ensure their successful development. The particles are produced in a specialized ovarian tissue of the female wasp named calyx. Virions are assembled in the calyx cell nuclei and stored in the oviduct before being transferred to the parasitoid host upon female wasp oviposition. Genes encoding proteins associated with the particles had been previously identified. These genes are localized in clusters of genes in the wasp genome (named IVSPER for "Ichnovirus structural proteins encoding regions"), they are specifically transcribed in the calyx but not encapsidated. IVSPER genes were thus hypothesized to derive from the integration of a virus, however still undetermined. Indeed, none of the identified genes had similarity to known sequence, making in addition unclear their function in particle production. In this work, we use the RNA interference technology to decipher the function of six IVSPER genes from the ichneumonid wasp Hyposoter didymator. Thanks to this approach, combined with transmission electron microscopy, we show that the studied IVSPER genes are required in different steps of particle morphogenesis and trafficking, and that their functions are those expected of a typical virus

Identification of a viral gene essential for the genome replication of a domesticated endogenous virus in ichneumonid parasitoid wasps

International audienceThousands of endoparasitoid wasp species in the families Braconidae and Ichneumonidae harbor "domesticated endogenous viruses" (DEVs) in their genomes. This study focuses on ichneumonid DEVs, named ichnoviruses (IVs). Large quantities of DNA-containing IV virions are produced in ovary calyx cells during the pupal and adult stages of female wasps. Females parasitize host insects by injecting eggs and virions into the body cavity. After injection, virions rapidly infect host cells which is followed by expression of IV genes that promote the successful development of wasp offspring. IV genomes consist of two components: proviral segment loci that serve as templates for circular dsDNAs that are packaged into capsids, and genes from an ancestral virus that produce virions. In this study, we generated a chromosome-scale genome assembly for Hyposoter didymator that harbors H. didymator ichnovirus (HdIV). We identified a total of 67 HdIV loci that are amplified in calyx cells during the wasp pupal stage. We then focused on an HdIV gene, U16 , which is transcribed in calyx cells during the initial stages of replication. Sequence analysis indicated that U16 contains a conserved domain in primases from select other viruses. Knockdown of U16 by RNA interference inhibited virion morphogenesis in calyx cells. Genome-wide analysis indicated U16 knockdown also inhibited amplification of HdIV loci in calyx cells. Altogether, our results identified several previously unknown HdIV loci, demonstrated that all HdIV loci are amplified in calyx cells during the pupal stage, and showed that U16 is required for amplification and virion morphogenesis